Ignoring details associated with friction, extra forces exerted by arm and leg muscles, and other factors, we can consider a pole vault as the conversion of an athlete’s running kinetic energy to gravitational potential energy. If an athlete is to lift his body 4.8 m during a vault, what speed must he have when he plants his pole?

Respuesta :

Answer:

9.7 m/s

Explanation:

Considering the law of conservation of energy, potential energy equals kinetic energy and since

Potential energy= mgh while kinetic energy =[tex]0.5mv^{2}[/tex]

Then [tex]gh=0.5v^{2[/tex] where g is acceleration due to gravity, m is mass, h is height and v is the velocity.

Taking g as 9.81 and height given as 4.8 m then

[tex]9.81*4.8=0.5v^{2}[/tex]

[tex]v=\sqrt {2*9.81*4.8}=9.704431977 m/s\approx 9.7 m/s[/tex]